SMART overall-health state

Attributes Threshold Values

These are defined by the vendor.

Attributes Worst Value

Note that some vendors firmware may actually increase the "Worst" value for some rate-type Attributes.

Attributes Type

Note that if an Attribute is of type 'Pre-fail', it does not mean that your disk is about to fail!
It only has this meaning if the Attribute's current Normalized value is less than or equal to the threshold value.

Column Updated

Some SMART attributes values, that are updated only during off-line data collection activities are labeled "Offline" in column "UPDATED".

Column "When Failed"

If the Attribute's current "Normalized value" is less than or equal to the threshold value, then the attribute is marked with "FAILING_NOW" in column WHEN_FAILED.

Raw Values

Please keep in mind that the conversion from RAW value to a quantity with physical units is not specified by the SMART standard!
smartctl only reports the different Attribute types, values, and thresholds as read from the device.
It does not carry out the conversion between "Raw" and "Normalized" values: this is done by the disk's firmware.

In most cases, the values printed by smartctl are sensible.
For example the temperature Attribute generally has its raw value equal to the temperature in Celsius.
However in some cases vendors use unusual conventions. For example the Hitachi disk on my laptop reports
its power-on hours in minutes, not hours. Some IBM disks track three temperatures rather than one,
in their raw values. Have a look at our wiki pages on topic SMART attributes.